Apparatus for printing a plate intended for offset printing, by passing through a photographic developing unit



Filed Oct. 5, 1964 Au 29, 1967 M HEMERY 3,338,149

APPARATUS FOR PRINTING A PLATE INTENDED FOR OFFSET PRINTING, BY PASSINGTHROUGH A PHOTOGRAPHIC DEVELOPING UNIT 4 Sheets-Sheet 1 M. HEMERY3,338,149 APPARATUS FOR PRINTING A PLATE INTENDED FOR Aug. 29, 1967OFFSET PRINTING BY PASSING THROUGH A PHOTOGRAPHIC DEVELOPING UNIT FiledOct.

4 Sheets-Sheet z M. HEMERY R O F DH w m N O M m? NT IG E N m TIP A S O LS L P A E P A V E G B D W ,C T G M N N P IIA R T R P N G I R R w 0 P 0 FT H W T F A A F R O A P P A 4 Sheets-Sheet 3 Filed Oct.

Aug. 29, 1967 M. HEMERY 3,338,149

APPARATUS FOR PRINTING A PLATE INTENDED FOR OFFSET PRINTING, BY PASSINGTHROUGH A PHOTOGRAPHIC DEVELOPING UNIT Filed Oct. 5, 1964 4 SheetsfiheetUnited States Patent 3,338,149 APPARATUS FUR PRINTING A PLATE INTENDEDFOR ()FFSET PRINTING, BY PASSING THROUGH A PHOTOGRAPH-III: DEVELOPINGUNIT Marc Hemery, Rue Pierre Brossolette, Clamart, France Filed Oct. 5,1964, Ser. No. 401,517 Claims priority, application France, Get. 11,1963, 950,404 6 Claims. (Cl. 9589) It is known to transfer, by passingthrough a photographic developing unit, the image of a negative of smallsize on to a printing form intended for offset printing (a grained metalplate).

The applicants have discovered that the kind of apparatus which lendsitself best to this transfer was that in which a central wetting deviceimpregnates the emulsion only of one of the two sheets of sensitivepaper employed, the other sheet being conveyed in the developer liquid.

- In an apparatus of this kind, it is not however sufficient tointroduce the negative into the single impregnation wetting side and theoffset plate into the developer bath in order to obtain completelysatisfactory results.

Amongst other adaptations, it was necessary to ensure perfectsynchronism in the simultaneous passage in complete agreement of thesetwo elements of very different natures which are the negative consistingof a sheet of sensitive paper and the offset form constituted by ametallic plate.

Failure to observe this condition resulted in offset printing which wasfuzzy, out of register, having defects and in a word unsatisfactory.

It will therefore be understood that up to the present time only offsetplates of small size have been printed, the printingof offset plates oflarge dimensions having been considered practically impossible until asatisfactory solution had been found.

This satisfactory solution has been provided by the present inventionwhich is the concurrent point:

of a fiat presentation of the negative and the plate at the exact levelof the contact generator line of the intake rollers of the developingapparatus;

of the accurate centering obtained between the negative and the plate;

I of perfect synchronism of the rotation of the intake rollers and thesqueeze rollers of the developing unit;

of a considerably increased length or span of the rollers and guidingtracks without the latter getting out of truth or buckling;

of the adjustment of the pressure of the rotating rollers.

The invention resides in the combination of a photographic developerunit and a centering table, the plane of which coincides with thegenerator contact line of the intake rollers of the developer unit, acommon driving device establishing perfect synchronism between therotation of the intake rollers and the squeeze rollers of the developerunit.

Guiding tracks, of which the essential feature of each is constituted bya series of parallel separate plates, held in position by cross members,permit the simultaneous displacement of the negative and the ofisetplate in perfect agreement.

The upper roller serving for the intake can be raised and lowered so asto permit the introduction of the negative and the offset plate into thedeveloper unit.

The upper intake roller is only lowered on the negative and the platewhen the latter have been effectively engaged in their respectiveguiding tracks.

An adjustable abutment enables a pre-determined position to be adoptedfor the offset plate on the centering table.

3,338,149 Patented Aug. 29, I967 also adjustable, on the centeringpositioning the negative with re- A transverse strap, table, is employedfor spect to the offset plate.

The developing unit preferably comprises at least one wetting roller,the direction of rotation of which is the same as that of the intakerollers, which facilitates the impregnation of the negative.

Other particular features and advantages of the present invention willbe brought out in the description which follows below, reference beingmade to the accompanying drawings, in which:

FIGURE 1 shows a perspective view of an apparatus according to theinvention permitting the printing of plates intended for offsetprinting;

FIGURE 2 is also a view in perspective, but partial, so as to show theguiding track of the offset plate;

FIGURE 3 is a view in perspective of the apparatus showing the guidingtrack of the negative, together with the device for driving insynchronism the intake rollers and the squeeze rollers;

FIGURE 4 is a view in partial perspective of the squeeze rollers of thedeveloper unit;

FIGURE 5 shows the application device of a pressure roller, insertedunder a squeeze roller.

In the form of construction shown, the developer unit or developer is ofthe type comprising two guiding tracks, one upper, the other lower, withrespect to two central wetting cylinders 3 and 4.

Intake rollers A and B are provided at the inlet of the developer, andtwo squeeze rollers C and D are arranged at the outlet of this samedeveloper. The roller A has the special feature that it can be raisedand lowered (arrows f and f This movement of the roller A isadvantageous ly obtained by mounting the roller A on two pivoted levers5 and 6 with an operating handle 7.

The wetting rollers 3 and 4 preferably rotate in the same direction asthe intake rollers, which facilitates the wetting of the negative whichcomes into contact with them. In fact, the negative is not soaked butsimply moistened, which contributes to its conveyance in perfectagreement with the plate, in view of its flexible nature as comparedwith the more rigid plate.

In front of the developer unit is arranged a centering table 8. This isintended to support, in a plane coincident with the contact generatorline of the rollers A and B, a metal offset plate (positive) and anegative sensitive support.

While they are resting on the table, the plate and the negative supportare sufiiciently engaged in their respective guiding track of thedeveloper (lower track for the plate and upper track for the negativesupport). This engagement of the negative and the plate naturallyimplies the lifting of the roller A (h).

The relative position of the plate and the negative can be modified byadjusting the respective positions of two abutment means provided on thecentering table. The offset plate rests directly on the table and itsposition is set by means of a cylindrical abutment 9.

The position of the negative, which rests in turn on the plate, isadjusted by means of a transverse strap 10.

The cylindrical abutment 9 passes across the table 8 by a longitudinalslot 11 formed in the table. A knurled nut 12 is screwed on the abutment9 so as to be capable of immobilizing it at a selected point along thelength of the slot 11 (arrow 3).

The strap 10 can pivot (arrow f about a longitudinal rod 13 parallel tothe table and fixed thereto by studs 13a. A knurled screw 14 permits thestrap to be fixed at any desired point on the length of the rod 13(arrow f In this way, the offset 15 is prevented from sliding in anydirection opposite to that of its introduction into the developer unit.This immobilization may be different, de-

3 pending on the position occupied by the adjustment stop 9 in the slot11.

In its turn, the strap 10 swung back on the plate, also prevents thenegative 16 from moving in the direction opposite to that of itsintroduction into the developer unit. The position of the strap 10 alongthe rod 13 enables the negative to be immobilized on the plate, whileleaving more or less space between the edges of these latter.

The lateral movement of the strap 10 enables this space to be varied atthe beginning of the operation. This spacing between the negative andthe plate is not capable of varying between the beginning and the end ofthe operation because of the perfect synchronism established between therotation of the intake rollers and the squeeze rollers. A systemcomprising a belt 17 and motor 18 drives in synchronism the pulleys 19keyed on the shafts of the roller B, of the wetting rollers 3 and 4 andthe squeeze roller D.

The essential element 1 of the upper guiding track and the essentialelement 2 of the lower guiding track are both constituted by profiledparallel plates 20, main tained at regular spacing by means of the crossmembers 21.

This construction enables the guiding tracks to be given a substantiallength, capable of receiving negatives and offset plates of largedimensions.

The negative passes between the element 1 of the upper track and thewetting rollers 3 and 4, while the offset plate travels between twoplates 22 and 23 facing each other, and the element 2 of the lowertrack. The plates 22 and 23 can be fixed by the screws 22a, 2311, on theend plates a of the element 2, which are slightly higher than theprofiled plates 20.

The lower track rests in a tank 24 supplied with developer liquid by adeformable pocket 25 intended to be compressed by a pressure device 26with an operating handle 27. A bag for recovering the spent bath (notshown) may be provided in the apparatus.

The intake rollers may be provided with a clutch 28 having a handle 28a,which enables these rollers to be released before the roller A islifted, and prevents any displacement between the teeth of the pinions aand b of the rollers A and B (the roller A being driven by the roller B)when the drive is re-applied.

The fiat presentation of the negative and the plate at the level of thecontact generator line of the intake rollers is effected in a strictlyaccurate manner by means of a water-level 29 provided on the centeringtable.

By reason of this flat presentation and of the synchronism of rotation,the centering. selected between the negative and the plate is maintainedfrom the beginning to the end of the printing operation of the offsetplate.

The intake rollers, the wetting rollers and the squeeze rollers may bemounted on a cradle 30 composed of parallel end-plates 30 and 31,resting on a base 32.

The position of the cradle on the base can be regulated by means oflevel screws 33, which contribute to a perfect adjustment of thesimultaneous travel of the negative and the offset plate in perfectagreement.

The parallelism between the squeeze rollers C and D in particular (whichare of great length) may possibly not be absolutely accurate, and inthis case an extremely simple expedient can be employed, consisting ofan auxiliary pressure roller E inserted under the lower roller D.

The pressure can be applied by means of a lateral lever 34 coupled by arod 35 to a second lever 36 which carries the shaft 37 of the pressureroller E.

A receiving table can be provided at the outlet of the squeeze rollersfor the offset plate.

Finally, a cover 39 may be provided to close the developer unit and thetank 24 may be provided with a level indicator 40.

In a general way, the description above has only been given by way ofexplanation and not in any limitative sense, and the invention iscapable of numerous alternative forms in conformity with its scope.

I claim:

1. Apparatus for printing a metallic offset plate from a sensitizedpaper negative comprising a centering table having leveling means,

a pair of intake rollers located at one end of said centering table withtheir generator contact line aligned in a plane with the top surface ofsaid centering table,

two guiding tracks aligned to receive plate and negative from saidintake rollers,

a mounting means suporting said pair of intake rollers and said guidingtracks,

wetting rollers and squeeze rollers also supported on said mountingmeans,

auxiliary pressure means to maintain said squeeze rollers in parallelalignment to each other,

and motor and belt means attached thereto with said belt means insynchronized driving connection with said intake and squeeze rollers,-

said mounting means including a base,

a cradle resting on said base, and

leveling screw means to regulate the position of said cradle on saidbase.

2. The apparatus for printing an offset plate in claim 1 furthercharacterized by said auxiliary pressure means including a pressureroller located for contact pressure with one of said squeeze rollers.

3. The apparatus for printing an offset plate in claim 1 furthercharacterized by said leveling means on said centering table being awater level attached thereto.

4. The apparatus for printing an offset plate in claim 1 furthercharacterized by said centering table having adjustable abutment meansto adopt a predetermined position for the offset plate on said centeringtable.

5. The apparatus for printing an offset plate in claim 4 furthercharacterized by said centering table having an adjustable transversestrap means to position the negative with respect to the offset plate.

6. The apparatus for printing an oifset plate in claim 1 furthercharacterized by at least one of said wetting rollers having a directionof rotation the same as that of said intake rollers thereby faciliatingthe wetting of the negative.

References Cited UNITED STATES PATENTS 2,775,933 1/1957 Malone et al 89XR 2,786,401 3/1957 Briggs et al 95-89 3,107,596 10/1963 Arnold et a195-89 3,257,927 6/1966 De Belder 95-89 NORTON ANSHER, Primary Examiner,

FRED L. BRAUN, Assistant Examiner.

1. APPARATUS FOR PRINTING A METALLIC OFFSET PLATE FROM A SENSITIZEDPAPER NEGATIVE COMPRISING A CENTERING TABLE HAVING LEVELING MEANS, APAIR OF INTAKE ROLLERS LOCATED AT ONE END OF SAID CENTERING TABLE WITHTHEIR GENERATOR CONTACT LINE ALIGNED IN A PLANE WITH THE TOP SURFACE OFSAID CENTERING TABLE, TWO GUIDING TRACKS ALIGNED TO RECEIVE PLATE ANDNEGATIVE FROM SAID INTAKE ROLLERS, A MOUNTING MEANS SUPPORTING SAID PAIROF INTAKE ROLLERS AND SAID GUIDING TRACKS, WETTING ROLLERS AND SQUEEZEROLLERS ALSO SUPPORTED ON SAID MOUNTING MEANS, AUXILIARY PRESSURE MEANSTO MAINTAIN SAID SQUEEZE ROLLERS IN PARALLEL ALIGNMENT TO EACH OTHER,AND MOTOR AN BELT MEANS ATTACHED THERETO WITH SAID BELT MEANS INSYNCHRONIZED DRIVING CONNECTION WITH SAID INTAKE AN SQUEEZE ROLLERS,SAID MOUNTING MEANS INCLUDING A BASE, A CRADLE RESTING ON SAID BASE, ANDLEVELING SCREW MEANS TO REGULATE THE POSITION OF SAID CRADLE ON SAIDBASE.